Open Collections

Calorific value of wood pellets

University of British Columbia

The export of wood pellets from Canada to Europe has been increasing steadily in recent years (roughly 1.8 million ton in 2013). Due to distances involved, wood pellets remain in transit and storage for months before their final consumption. The net calorific value determines the price of wood pellets purchased in Europe. There have been concerns about the changes of net calorific values over time. In this study, the effects of storage time, storage configuration, storage temperature, and wood pellet quality on the net calorific value of wood pellets for a period of 6 months were investigated. Storage configurations were “open” or “closed” and storage temperatures were 25°C, 35°C and 45°C. Two types of wood pellets used: white (10% bark) and mixed (40% bark). The results in the “closed” storage scenario indicated that storage time had a positive effect on the net calorific value, where the net calorific value increased by 1 to 2% over the storage period. In the open storage scenario, the moisture content had the most significant impact on the net calorific value. A multivariable linear regression and analysis of variance performed verified the graphical results. It was postulated that the higher energy potential compounds – low molecular weight aldehyde and ketone or off-gasses such as carbon monoxide, methane and hydrogen – produced during pellet storage, caused the increase in net calorific values.

Text

2015-01-07

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/51791

Chemical and Biological Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/